Dotenv\Loader::resolveNestedVariables PHP Method

resolveNestedVariables() protected method

Look for {$varname} patterns in the variable value and replace with an existing environment variable.
protected resolveNestedVariables ( string $value ) : mixed
$value string
return mixed
    protected function resolveNestedVariables($value)
    {
        if (strpos($value, '$') !== false) {
            $loader = $this;
            $value = preg_replace_callback('/\\${([a-zA-Z0-9_]+)}/', function ($matchedPatterns) use($loader) {
                $nestedVariable = $loader->getEnvironmentVariable($matchedPatterns[1]);
                if ($nestedVariable === null) {
                    return $matchedPatterns[0];
                } else {
                    return $nestedVariable;
                }
            }, $value);
        }
        return $value;
    }